Jenkins 2.251 and earlier, LTS 2.235.3 and earlier does not escape the tooltip content of help icons, resulting in a stored cross-site scripting (XSS) vulnerability.
https://jenkins.io/security/advisory/2020-08-12/#SECURITY-1955
http://www.openwall.com/lists/oss-security/2020/08/12/4
http://packetstormsecurity.com/files/160443/Jenkins-2.235.3-Cross-Site-Scripting.html